Reigning world champion Sebastian Vettel said he was pleased with Red Bull’s progress despite having his running halted twice because of reliability issues on day two of the Barcelona test.

Vettel, 25, was forced to suspend his running during a race simulation run in the afternoon session to investigate a hydraulic pressure issue and then the German brought out the red flag after stopping on the exit of the pit lane with a loose wheel.

Despite the problems, the German still clocked up 84 laps and finished the day second fastest, 0.349 seconds slower than pacesetter Sergio Perez in the McLaren.

Vettel said: “We had issues with reliability and couldn’t do as many laps as we wanted but it’s better that these things happen today rather than in Australia.

“It was nothing dramatic, just small things. We had to stop the car once as we saw a small loss of pressure and then towards the end of the day it looks like after the stop the wheel wasn’t on properly.

“So I had to stop again, cause the red flag and it just takes too much time to turn everything around, so we couldn’t get out again.

“We are pretty happy with the car, with the balance, how it feels. This morning, we did a couple of short runs with new tyres and a little less fuel.

“This afternoon was a different story. It’s fairly difficult to read because the tyres are such a dominant factor but I think we’re there or thereabouts from what we can see.”

“However, though we would obviously much rather have had a smooth run today we still accomplished a lot and even managed to slot in some more test items in the afternoon, which we put on the car at lunch time. So, while it wasn’t an ideal day, we did get through most of what we wanted to.”

Vettel will hand the car over to team-mate Mark Webber for the remaining two days of the test. The final four-day pre-season test begins on 1 March in Barcelona.